1. Technology Field
The invention relates to a connecting interface unit, and more particularly, to a connecting interface unit not including a crystal oscillator, and to a memory storage device using the connecting interface unit.
2. Description of Related Art
Along with the rapid growth of the market for digital cameras, cell phones, and MP3 players in recent years, consumers' demand for storage media has increased drastically. Due to their characteristics such as data non-volatility, low power consumption, compact size, and non-mechanical structure, rewritable non-volatile memory modules (e.g. flash memory) are very suitable for being built in the above exemplified portable multimedia devices.
Generally speaking, a rewritable non-volatile memory module is coupled to a host system via a connecting interface unit. Such connecting interface unit is compliant with a transmission standard, for example, a Universal Serial Bus (USB) standard. Data transmitted between the host system and the connecting interface unit is transmitted at a specific frequency. Hence the connecting interface unit is required to be able to generate a clock signal at this specific frequency. In order to comply with the specification of the transmission standard, the frequency of such clock signal must be stable. Accordingly, the clock signal is generally generated by a crystal oscillator disposed in the connecting interface unit. However, compared to other types of oscillators, crystal oscillators cost more. Besides, as the connecting interface unit changes in temperature, the characteristics of the oscillators may be altered so that deviation occurs in the frequency of the clock signal. Therefore, persons skilled in the art are concerned about how to design a connecting interface unit without use of a crystal oscillator and to make the connecting interface unit comply with the specification of a transmission standard.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.